The purpose of our research is to study temporal processing of sensory (auditory) information in psychiatric patients. Psychophysical and psychomotor techniques are used to obtain precise and valid measures of patient vs. non-patient differences which reflect the sensory function under investigation rather than attitudinal (motivational, criterion, etc.) variables. The proposed research attempts to clarify and extend our prior findings in which a sub-group of patients showed elevated auditory forced-choice thresholds and also differences in their reaction time measures of monaural temporal interactions compared to non-patients. Experiment 1 further investigates monaural temporal interactions of transients (clicks) in patients and non-patients. Both forced-choice thresholds and reaction times will be measured to click pairs, varying the temporal interval between the clicks (delta t). The influence of several stimulus parameters, e.g., inter-pulse intensity ratio (delta I) and sensation level of clicks, on patient vs. non-patient differences in monaural temporal interactions will be explored. Our prior findings lead us to expect that a sub-group of patients may benefit more from the presence of the second click in a pair, i.e., show a greater reduction in threshold and/or reaction time, than non-patients. In Experiment 2, forced-choice thresholds and reaction times of patients and non-patients will be measured to noise bursts of variable duration. This will provide a test of possible auditory deficit of central origin in patients differing from non-patients in their performance on our threshold and reaction time measures.